NOVEC 1230 Suppression System: How to Design

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• Clean Agent Gas Suppression System

NOVEC™ 1230 is a relatively new clean agent fire extinguishing product developed by 3M. Dodecafluoro-2-methylpentan-3-one is the full chemical name. It follows NFPA clean agent standard as FK-5-1-12 and can be used as a halon replacement. It belongs to the halocarbons group which includes hydrofluorocarbon (HFC)s and fluoroketones. So it can be used as an alternative to existing HFC installation. It remains in liquid form at room temperature whereas other HFC based extinguishing agents are gas. NOVEC 1230 is very effective, safe, eco-friendly as well as cost-effective. We shall go in-depth about designing the Novec 1230gas suppression system with you. So sharpen your pencil and get ready.

NOVEC 1230 Gas suppression SYSTEM DESIGN Summary

For implementing an effective NOVEC 1230 gas suppression system, a proper engineering design is mandatory. To make a proper design you should follow the steps below. To keep the post size not too long we divide the system design into two parts.

Part 1

• Before Starting
• Study on hazard
• Determining hazard Class
• Knowing the Encloser
• Determining agent quantity
  • Determining hazard volume (V)
  • Selecting Concentrate Percentage (C)
  • Knowing the Flooding factor table (F.F)
  • Using Atmospheric Correction Factor (CF)

Part 2

• Positioning the Cylinder
• Selecting the nozzle
• Nozzle positioning
• Pipe network planning
• Selection of detectors
• Positioning of detectors
• The positioning of Audiovisual alarm devices
• Reviewing System design

Before Starting the design of NOVEC 1230 GAS SUPPRESSION SYSTEM

NOVEC 1230 Clean Agent Fire Suppression System is in general not too complex to design. Most of the cases you might procure a pre-engineered system that further reduces the effort needed to design an effective system. There are things you should have in your hand before starting the design process.

• It is recommended to select a manufacturer before starting the design. Every brand that manufactures NOVEC 1230 Clean Agent Fire Suppression System provides a system manual. You can get them from their websites. We should follow their instruction for effective design.
• You should thoroughly study the Material Safety Datasheet (MSDS) to understand the effect of the agent on human. If there is a probability for personnel to be exposed in the agent for a longer time than recommended, measures shall be taken in the design to limit the exposure. Adding an exit can be a way.
• You should have a copy of NFPA 2001:Standard on Clean Agent Fire Extinguishing Systems. It will help you standardized your design. Most of the time customers ask to follow this standard.
• You also should study if any specific instructions are provided by Authority Having Jurisdiction(AHJ).

Study on hazard FOR DESIGNING OF NOVEC 1230 GAS Extinguishing SYSTEM

Evaluating hazards is the first step to design the NOVEC 1230 Clean Agent Fire Suppression System. Hazard is defined within the limitations established by NFPA 2001, UL, FM, or other third parties approvals. Following properties should be checked during analyzing a hazard:

• Minimum & Maximum temperature can develop during normal operation in the protection area.
• Ambient temperature
• Hazard Class
• The integrity of the encloser

Determining hazard Class

National Fire Protection Association (NFPA) classifies fire based on the combustible material that can possibly catch fire. There are 5 classes of fire ie Class A, B, C, D, and K. NOVEC 1230 Clean Agent Fire Suppression System is only recommended to use in Class A, B and C. The designer must know the Hazard Class to make an informed decision about selecting a percentage of design concentration, agent quantity, etc.

Class A:

Everyday use solid items such as paper, wood, fabrics, rubber, cloth, etc

Class B:

Flammable liquid or gas such as Diesel, Natural Gas, etc

Class C:

Any type of electrical Fire

Knowing the Encloser for designing of NOVEC 1230 GAS SUPPRESSION SYSTEM

Encloser has major effects on the design of NOVEC 1230 Clean Agent Fire Suppression System. If ambient pressures vary more than 11 percent from standard sea level pressures, the design quantity of NOVEC 1230 needs to be adjusted.
A minimum concentration of 85 percent of the adjusted minimum design concentration shall be held at the highest height of protected content within the hazard for a period of 10 minutes or for a time period sufficient to allow for response by trained personnel. If there are any unclosable openings in the protected enclosure than it should be kept to a minimum. Although It is better to ensure all openings are capable of being closed at the time of agent discharge.

DETERMINING AGENT QUantity for NOVAC 1230

We can use these two formulas to find out the minimum required amount of NOVEC 1230:
Formula 1:

W = V * C.F. * F.F.

W = weight of agent
V = volume of the protected enclosure
F.F. = flooding factor
C.F. = atmospheric correction factor

Formula 2:

s = 0.0664 + 0.0002741*t

W = weight of agent
V = volume of the protected enclosure
C.F. = atmospheric correction factor
s = specific volume of superheated Novec 1230 fluid vapor
t = design temperature in the hazard area
C = concentration of agent required

This calculation includes an allowance for the normal leakage from a “tight” enclosure due to agent expansion.

DETERMINing THE HAZARD VOLUME (V)

1. The calculation of the hazard volume is very easy indeed. We just needed to multiply the Length (L), the Width (W), and the Height (H) of the room/compartment to find out the Volume (V). So the equation is V= LxWxH
2. Now we need to deduct the volume of solid, non-permeable, and non-removable objects, permanent structures, or equipment.
3. To get the actual protecting volume we need to deduct step 2 from step 1.

Selecting concentrate percentage (C) for NOVAC 1230

We selected the Hazard Class previously. Now it is time to calculate the quantity of Novec 1230 fluid required to provide the effective design concentration. For example, we can use 4.2% as design concentration for protecting Class A or Class C hazards as per the chart below

Knowing NOVAC 1230 FLOODING FACTOR (FF) TABLE – METRIC Unit

• W/V [agent weight requirements (kg/m³)] = pounds of agent required per m³ of protected volume needed to produce the indicated concentration at the temperature specified.
• t [temperature (°C)] = the design temperature in the hazard area.
• s [specific volume (m³/kg)] = specific volume of superheated Novec 1230 vapor as approximated by the formula: s = 0.1269 + 0.0005(t),
  where t is in °C
• C [concentration (%)] = volumetric concentration of Novec 1230 in air at the temperature indicated.
  

USING NOVAC 1230 Atmospheric Correction Factor (C.F)

Wait… wait ..wait… we are not done yet. Finally, we find out the agent quantity. Eventually, we have to focus on storage cylinder, pipe network, nozzles, and detection system design.

NOVEC 1230 CYLINDEr Selection and positioning

The cylinder containing NOVEC 1230 is selected based on the required quantity we have found from the calculation previously. Often time, your required quantity does not match with the manufacturer’s standard models. In this case, you have to select the nearest big size cylinder model available. If you need for than one cylinder to protect the occupancy and they supply to the same manifold outlet for distribution, then all cylinders should be of the same size and pressure class.

Mounting the NOVEC 1230 is unquestionably important. It helps to retain the weight of the storage container and balance the reaction force in the event of a discharge. We should position the Cylinder in a safe, accessible, far from high traffic areas and convenient location though it needs a minimum agent travel during a discharge. We also should make sure cylinders are free from any type of damage.

Cylinders and accessories should be arranged in such a way that the inspection, testing, commissioning, recharging, and other maintenance activities in effect become easy. If we do it properly, we can reduce the downtime of the NOVEC 1230 gas suppression system to a minimum.

Selecting the nozzle for NOVEC 1230

In general, we select nozzle on the basis of listed performance data that clearly depicts the interrelationship of NOVEC 1230 clean agent quantity, discharge rate, discharge time, area coverage, and the distance of the nozzle from the protected surface. In fact, every manufacturer has different models of nozzles. But we can categorize all of them into two types.

1. 360° nozzle: This type provides a full 360° discharge pattern designed for placement in the center of the hazard.
2. 180° nozzle: This provides a 180° discharge pattern designed for placement adjacent to a sidewall of the hazard.

Both type nozzles are available in different sizes. ½ in (15 mm), 1 in (25 mm), 1 ½ in (40 mm), 2 in (50 mm), and 2 ½ in (65 mm) sizes are the most popular. You should select nozzle size based on the maximum permitted time to extinguish a fire and the system discharge rate ( the sum of the individual rates of all the nozzles).

Nozzle positioning for NOVEC 1230

The nozzles shall only be used in the system with which they are listed as we told before. They shall be placed within the protected enclosure in compliance with listed limitations with regard to spacing, floor coverage, and alignment. Generally, you can get all this information from the manufacturer installation manual. In particular, Area and Volume coverages of the nozzle should not exceed. You should mind that the maximum volume varies as a function of minimum design concentration and minimum temperature.

A sufficient number of nozzles shall be used to cover the entire hazard area on the basis of the unit areas protected by each nozzle, but you should not forget the limitations stated in nozzle listings. Nozzles shall be located above or below of protected surfaces. Nozzles shall be located so as to be free of possible obstructions that could interfere with the proper projection of the discharged agent.

Pipe network planning for NOVEC 1230

Most of the cases manufacturers use specialized flow calculation software for pipe network planning. But you can design a system without software as long as you follow nozzle selection, pipe size, and pipe length limitations provided by the manufacturer.

You can use the following table as an estimation guide for the sizing of distribution piping. We recommend to use the Flow Calculation software before finalizing the design.

Selection of detectors for NOVEC 1230 GAS Suppression System

During the planning of the fire detection system, the choice of detectors is critical for ensuring proper performance. Hazard type, floor height, coverage area, detector aerodynamics, and sensor response, and other factors play an important role in the selection of detectors. In the Novec 1230 gas suppression system, smoke detectors are mostly used due to its detection time is much lesser than heat detectors. Generally, two types of smoke detectors are common in the gas suppression system. They are

Positioning of detectors

We recommend following NFPA 72 and manufacturer product listing to design Detectors. Photoelectric smoke detectors are usually installed on the ceiling, not less than 4 in. (0.1 m) from the wall. If their listing permits, they are also permitted to be installed on the wall, with their highest edge no less than 4 in. (0.1 m) and no more than 12 in. (0.3 m) from the ceiling. You should not install detectors in an air stream from an HVAC supply grill, because that will inhibit smoke from a fire in the protected space from reaching the detector.

For air sampling–type smoke detectors installation please check here.

The positioning of Audiovisual alarm devices for NOVEC 1230

A fire alarm system that simply sounds an audible signal and flashes strobe lights in space is
conveying a single bit of information—fire alarm. Selecting, positioning, and installing of audiovisual alarm devices should be done by following NFPA 72.

Audible notification appliances are the most common. Their placement, decibel setting, frequency, and length of the signal are calculated according to numerous factors, for example, the physical parameters of the area being protected.

Visible notification appliances usually supplement the audible alarm system but in certain cases (such as loud ambient noise) they may be the primary alarm system. As with audible systems, the design of visual notification appliances must use many calculations based on a variety of factors, including the physical properties of light.

Reviewing novec 1230 System design

We already have gone through all the steps needed to design a NOVEC 1230 Gas suppression system. There some additional things to incorporate into our design (mostly in detection part) such as doors, air-handling equipment, damper, etc. These mechanical items need to close immediately after detecting a fire.

We should especially verify that the design reflects customer requirements. If there are issues where you need customer concern, then you should communicate with them to resolve it.

We are hoping you enjoyed the detailed guideline, after all, we do it for you only. If you have any question you can comment below. We shall get back to you soon. Happy designing…